1. Field of the Invention
The present invention relates to a flexible printed circuit board (FPC).
2. Description of Related Art
A known printed circuit board is an indispensable component in electric and/or electronic devices nowadays. In a printed circuit board in general, a circuit, comprising a plurality of lines, for electrically connecting IC-chips, resistors, capacitors and so forth, is made by conductive thin copper foil lines, and an insulative base plate, on which the circuit is printed. A printed circuit board having such a structure has been widely used due to accuracy for circuit arrangement, and compactness and easy-assembly for installation into devices.
As a type of improvement from the printed circuit board, a flexible printed circuit board (FPC) has been developed. In addition to the merits mentioned for the printed circuit board, a flexible printed circuit board can be laid out with high degree of freedom due to flexibility in narrow spaces in machines and devices. This has been considered one of merits for a flexible printed circuit board.
By such a flexible printed circuit board, most of designed circuits can be, in principle, printed. However, for example, on a flexible printed board used for a camera, it is impossible to lay out circuits for a power supply and a strobe device, which usually require a wider copper foil line for a large current. If such a wider copper foil line is laid out on a FPC board, spaces for other lines have to be sacrificed. Accordingly, in a prior art, circuits requiring a large current are formed on a separate FPC board mainly for the purpose of collectively providing standard copper foil lines on a main FPC board. This separate FPC board and the main FPC boards are connected by lead wires, or lead wires themselves are used instead of flexible circuit boards for power supply and a strobe device.
In such an arrangement mentioned above, the number of parts increases, assembling-time is also made longer. In addition, spaces for installing both flexible printed circuit boards and lead wires have to be secured. Accordingly, manufacturing costs inevitably increase.